机械产品可靠性及模糊可靠性研究

讨论了机械产品可靠性研究的必要性和常规可靠性理论的局限性,分析了模糊可靠性理论产生的背景,揭示出模糊可靠性研究的特点和意义。     

基于GT的过程机械快速设计系统的开发

过程机械的设计直接关系到产品的质量、成本和可靠性。在分析过程机械设计的特点和现状的基础上,运用成组技术构建了一个基于成组技术的过程机械快速设计系统,并且对开发过程中的零件分类方法、GT码的编制、编码检索与相似性判别以及三维设计系统的二次开发等关键技术进行了阐述。快速设计系统的使用可以缩短产品设计周期,使产品快速面市,提高产品的竞争力。     

如何通过设计提高钻探机械的可靠性

钻探机械的可靠性直接关系着产品的质量和使用性能，同时也关系着工程施工过程中操作人员的安全性，因此必须提高其使用可靠性。产品设计的好坏直接关系着产品的可靠性，因此必须提高产品设计质量。本文就钻探机械产品的传统设计和先进设计方法进行了探讨，为钻探机械产品的设计提供了参考依据。     

机械零部件的可靠性优化设计探究

机械产品的可靠性是衡量机械产品质量的一个重要指标,随着科学技术的发展,对机械产品的可靠性要求也日益提高。要提高机械产品的可靠性,必须首先从设计上解决机械产品的固有可靠性要求,然后在制造中加以保证。具有良好的可靠性指标是使我国机械产品在国际市场上具有竞争力的重要保证,机械零部件的可靠性优化设计其重要性不言而喻。机械零部件的设计不仅需要的是与时俱进、把脉时代的创新精神,更需要把握零部件质量保证和可靠性优化设计的科学方法。     

机械可靠性与维修性的整合设计及在工程机械中的实践探索

新的经济发展形势对工程机械的可用性提出了更高的要求,而机械产品的可靠性和维修性共同决定着产品的可用性。因此,对机械可靠性与维修性的整合设计进行研究具有非常重要的现实意义。本文通过对机械可靠性与维修性的整合设计及其在工程机械实践工作中的应用进行研究,提出工程机械可靠性与维修度整合设计的相关方法,以便从设计环节提高工程机械产品的可靠性和维修性,从而改善当前国内工程机械产品可靠性维修性较低这一现状,保证其在使用过程中的可用性。     

工程机械零件的可靠性优化设计

通过对机械产品可靠性的评价,分析了传统设计方法与可靠性设计方法在设计思想、设计原理上的区别.运用可靠性理论与最优化设计技术,提出了机械零部件的可靠性优化设计方法.在满足可靠度约束及结构几何约束的条件下,以体积最小作为优化目标函数进行可靠性优化设计,得到了比常规设计更为合理的设计结果.     

齿轮齿根弯曲强度的可靠性设计

本文介绍了机械可靠性设计的基本理论、常用的可靠度计算方法。由于齿轮强度的可靠性设计较为复杂,目前还没有系统的可靠性设计式,文中只对齿根弯曲强度计算式中各随机变量参数进行了分析,并推导出齿根弯曲强度的可靠性设计式,可为推广我国机械产品的可靠性设计作参考。     

如何提高机械产品的可靠性

２１世纪产品竞争的焦点是产品的可靠性。只有那些具有高可靠性的产品的企业才能在日益激烈的国际贸易竞争中生存下来。本文就我国机械产品目前如何切实提高可靠性的问题进行研究后提出：可靠性设计是基础和保证，对现有的产品必须进行可靠性设计内容的补课；对机械产品进行全方位的可靠性质量管理是关键，而可靠性人才培养是目前急需解决的首要问题。     

可靠性设计在机械设计中的应用

现代机械设计中,可靠性是非常重要的内容,可作为机械产品质量以及产品使用寿命的重要指标,因此可靠性设计受到越来越多企业的重视。该文主要通过分析可靠性设计原则,探讨可靠性设计在当前机械设计中的具体应用,希望为相关设计人员提供一些有价值的参考。     

基于冲击衰减的竞争失效可靠性分析模型

针对经受竞争失效的机械产品其突发失效过程中冲击存在衰减的现象,根据冲击信号的衰减特性,提出了基于衰减冲击模型的竞争失效可靠性分析计算方法.该方法首先考察具有周期性和随机性特点的两类衰减冲击过程,利用指数函数描述其衰减规律,探讨冲击作用时所产生的冲量.在此基础上构建冲击所造成的损伤与冲量之间的量化模型,通过Wiener过程对连续退化进行描述,进一步推导产品在失效相关模式下的竞争失效可靠性分析模型.最后通过算例比较研究了考虑冲击衰减与否对可靠性评估的差异,为产品可靠性设计提供参考.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.